Bladder exstrophy patients who have undergone primary bladder closure, but have a bladder capacity too low for bladder neck reconstruction (Group 1), have limited additional surgical options that permits urethral voiding and urine storage within a native bladder. Previous studies have demonstrated a positive correlation between bladder capacity and success of bladder neck reconstruction. Likewise, patients who have undergone bladder neck reconstruction but continue to have urinary incontinence (Group 2) are also faced with limited options. Often, both groups are considered for augmentation cystoplasty with closure of the bladder neck requiring intermittent catheter voiding through a surgically constructed continent catheterizable channel. Such major reconstruction has significant associated short and long-term morbidities. Endoscopic injection of MDCs for the treatment of urinary sphincter insufficiency is a potential alternative therapy for these patients. By increasing the outflow resistance and rhabdosphincter contractility, MDC injection may permit more efficient bladder cycling and bladder expansion in Group 1 patients allowing them to proceed on to bladder neck reconstruction. This same increase in resistance and sphincter contractility may allow Group 2 patients to attain urinary continence and avoid any further reconstructive surgical procedures.